Field of the Invention
The present invention relates to coiled tubing used in oilfield operations.
Description of Related Art
Information concerning, for example, the temperatures and pressures exhibited within a wellbore is used to predict the production interval of the well. Knowledge of the production interval is used to enhance the recovery rate of a well and, in turn, make the well more economical to operate. Tools exist to retrieve such information relating to conventional wells that exhibit temperatures below about 204° C. (400° F.). In wells that exhibit higher temperatures, such as steam assisted gravity drainage (SAGD) wells, cyclic steam wells, and the like, design of such tools becomes difficult, as elastomer materials often cannot withstand such high temperatures.
Other downhole devices have been constructed to measure characteristics, such as temperature and pressure, within a wellbore. For example, one such conventional device employs a coiled tubing in which a plurality of capillary tubes is disposed. Some of the plurality of capillary tubes have temperature sensors disposed therein, while others of the plurality of capillary tubes are used to measure pressure. In high temperature applications, however, such coiled tubing devices are susceptible to failure due to fatigue.
There are devices for measuring characteristics, such as pressure and temperature, in a downhole environment that are well known in the art, however, considerable shortcomings remain.